1. Field of the Invention
The present invention relates to an apparatus for forming external electrodes on component chips for a electronic component, an apparatus for inserting the component chips into component holding holes of a component conveyer belt, an apparatus for coating with an electrode paste the component chips that are held within the component holding holes of the component conveyer belt, and the component conveyer belt for conveying the component chips in a state of being resiliently held.
2. Description of the Prior Art
Japanese Patent Application Laid-Open No. H6-215991 discloses an apparatus for forming external electrodes on both ends of a component chip. The apparatus has an endless belt having resilient masks with small apertures, sprockets having the endless belt wound there around, means for inserting component chips into the apertures in the resilient masks, means for coating with a terminal paste respective end portions of the component chips that are inserted into the apertures, and means for extracting the component chips with the paste coating out of the resilient masks.
In the above-noted apparatus, pins each having the same diameter as each of the apertures are used for inserting the component chips into the apertures in the resilient masks provided on the endless belt, moving the component chips within the apertures, or extracting the component chips out of the apertures. For this reason, if the centerline of each aperture should be slightly incorrectly aligned with the centerline of each pin, the tip of the pin would be caused to strike the opening edge of the aperture. In addition, the colliding pins are forcibly inserted into the apertures, resulting in damage to the apertures.
This misalignment may necessarily occur due to dimensional precision of the endless belt, the resilient mask or the like, which is difficult to be prevented. Therefore, if operations of inserting the components into the apertures, moving the components within the apertures, or extracting the components out of the apertures are repeatedly conducted, the damage to the apertures in the resilient masks will be caused to increase. As a result, there suffers from the disadvantage that the component chips may not be inserted into the apertures, the inserted component chips may be dropped out therefrom, or the like. Therefore, the expected external electrode formation will not be satisfactorily achieved.
An object of the present invention is to provide an external electrode forming apparatus for electronic components while reducing damage to the interiors of component holding holes formed in a component conveyer belt and performing a good external electrode formation on the component chips over a long time period.
In order to attain this object, according to the present invention, the external electrode forming apparatus comprises an endless component conveyer belt including rows of component holding holes in a longitudinal direction of the belt in parallel at equal intervals for resiliently holding the component chips, a belt feeding mechanism for intermittently feeding said component conveyer belt in a predetermined direction, a component-inserting machine for inserting the component chips into the component holding holes, with use of pressure pins, to project one end portion of each component chip from one surface of said component conveyer belt, a component-reversing machine for moving within the component holding holes the component chips that are held within the component holding holes, with use of pressure pins, to project the other end portion of each component chip from the other surface of said component conveyer belt, a paste-coating machine for coating with electrode paste the projection of each component chip that is held within each component holding hole, and a component-discharging machine for extruding the paste coated component chips from the component holding holes with use of pressure pins, wherein each pressure pin used in said component-inserting machine, said component-reversing machine, and said component-discharging machine has a taper portion with a tip shape which is smaller than said component holding hole at the tip part.
In the external electrode forming apparatus according to the present invention, since pressure pins each having a taper portion at the tip are available, impingement may be prevented upon the open-ended edges of the component holding holes. The pressure pins after the impingement may also be hindered from forcibly being inserted into the component holding holes, whereby damage to the interiors of the component holding holes can be extremely diminished. As a result, such inconvenience may be overcome as insertion failure or dropout of the inserted component chips to perform a good formation of external electrodes on the component chips over such a long period.
The aforementioned object and other objects, features and advantages in accordance with the present invention will be apparent in conjunction with the following description and appended claims, and the accompanying drawings.